He could feel the bunker above him crumbling. The dull thud of a new impact came every few seconds now, slow and relentless. He knew he couldn’t stay here. Before long, what little protection he had would be gone and it would only be a matter of time before it was all over. No, he had to fight. That much was clear now. It was just a question of timing. He shifted from side to side, nervously preparing himself for the moment he knew had to come. They were closer than ever and with every second he hesitated, they were advancing further still. Maybe if he waited until... No, damn it. It had to be now.

He threw himself out of the bunker, firing his gun blindly into the sky as he did so. One of the shots found its mark and he heard the high-pitched keening of a fallen enemy. Bombs were raining all around him now, cascading into the ground as he dodged and weaved between them. They would never hit him. He was a shadow. He was fluidity itself. They could come, rank by rank, and he would destroy them all. He was invincible.

It was then that he heard it. Somewhere far above, the undulating siren of a saucer.

Fanfiction is fan-written material that makes use of characters, ideas and settings from existing works of fiction. Here's what Wikipedia says about it and here's more than you could ever read. Careful, though – it's a murky world in there.

fantastic! how about some stargate fanfiction? or x-files! i'm fascinated with the formula shows like that follow. i can almost always predict how an episode is going to turn out just because the formula is so precise.

My very favorites are Donna the Vampire Slayer (Buffy x West Wing) and the series (here, here, here, here, here) that is Harry Potter x Miles Vorkosigan — the future of the Potterverse is the Vorkosiverse. And no, it isn't Miles who turns out to be from a Barrayaran wizarding family.